An Investigation Into Wastewater Treatment in the Three Gorges Reservoir Basin
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An Investigation Into Wastewater Treatment in the Three Gorges Reservoir Basin A Probe International Study By THE CHONGQING GREEN VOLUNTEERS ASSOCIATION Wu Dengming Lead Researcher February 2013 PROBE INTERNATIONAL EDITOR: PATRICIA ADAMS TABLE OF CONTENTS INTRODUCTION Page 1 BASIC INFORMATION ON METROPOLITAN CHONGQING − Area and Population Page 1 − Table 1: Districts of Metropolitan Chongqing Page 1 − Industry Overview Page 2 Page 2 WASTEWATER TREATMENT IN METROPOLITAN CHONGQING − Information Sources Page 3 − Basic Information Page 3 − Sewage Treatment Plants Page 3 − Table 2: Treatment Plants Managed by Chongqing Water Group Co. Page 5 Ltd. and Chongqing Water Resources Investment Group Co. Ltd. Page 6 − Figure 1: Chongqing Water Group Co. Ltd. and its Subsidiaries − Figure 2: The Distribution of Wastewater Treatment Plants in Page 8 Metropolitan Chongqing Page 10 − Current Challenges to Wastewater Treatment in Metropolitan Chongqing Page 11 WASTEWATER TREATMENT IN THE THREE GORGES RESERVOIR REGION (BELOW METROPOLITAN CHONGQING) Page 14 RECOMMENDATIONS Page 15 CONCLUSIONS Page 17 ENDNOTES Page 18 RESOURCES Page 21 APPENDIX 1: Wastewater Treatment in Metropolitan Chongqing Page 22 APPENDIX 2: Large and Medium-sized Wastewater Treatment Plants in Metropolitan Chongqing Page 23 APPENDIX 3: Wastewater Treatment Plants under Construction, Extension, and Proposed for Nine Districts of Metropolitan Page 25 Chongqing Introduction The Three Gorges Reservoir basin area is 490,000 square kilometres. The water quality of this basin directly affects the safety of all those who use and depend on it. Though the Chongqing Municipal Government1 has invested in more than 40 new large and medium-sized wastewater treatment plants in important cities in the Three Gorges Reservoir Region along the Yangtze River, the decreased flow rate of water caused by the construction of the Three Gorges Dam has robbed the river of its ability to self-purify. This decline in the rate of flow also means that pollutants carried by tributaries cannot be diluted or flushed away quickly by the Yangtze River, causing serious eutrophication in some tributaries. 2 In 2010, Metropolitan Chongqing , the old city within the The Three Municipality of Chongqing, dumped 451,800,000 tonnes of industrial wastewater and 829,330,000 tonnes of domestic Gorges Dam has wastewater into the Yangtze. The chemical oxygen demand (COD) robbed the of this wastewater was 234,500 tonnes.3 The sewage treatment Yangtze River of capacity of Metropolitan Chongqing is an important factor its ability to self affecting the water quality and ecology of the Three Gorges purify. Reservoir. In addition, downstream of Metropolitan Chongqing, hundreds of towns and chemical complexes are dumping industrial and domestic waste into the Yangtze, adding to the grave threat to water quality in the 600 km long reservoir area. This paper reviews wastewater production and treatment in the Three Gorges Reservoir Region with a special focus on Metropolitan Chongqing, which sits at the head of the reservoir created by the Three Gorges Dam. It also recommends institutional and regulatory reforms to reduce pollution, expand wastewater treatment, and protect water quality for all riparians living downstream of Metropolitan Chongqing, Basic Information on Metropolitan Chongqing Area and Population Located at the confluence of the Yangtze River and the Jialing River, Metropolitan Chongqing lies at the tail of the Three Gorges Reservoir Region. Spanning an area of about 5,500 square kilometres, Metropolitan Chongqing is home to a population of over 7.4 million (excluding its floating population). Metropolitan Chongqing consists of nine districts: Yuzhong, Dadukou, Jiangbei, Shapingba, Jiulongpo, Nan'an, Beibei, Yubei, and Ba'nan (see Table 1). 1 Table 1: Districts of Metropolitan Chongqing Population District Area (km2) (in thousands) Yuzhong 22.56 630 Dadukou 103 300 Jiangbei 213 738 Shapingba 396.2 1,000 Jiulongpo 432 1,080 Nan'an 265 759 Beibei 755 684 Yubei 1,452 1,340 Ba'nan 1825 918 Total 5463.76 7,449 Industry Overview The economic and technological development zones in Metropolitan Chongqing include:4 1) Chongqing Chemical Industrial Park 2) Chongqing Economic & Technological Development Zone 3) Chongqing Hi-Tech Industry Development Zone 4) Chongqing New North Zone (CNNZ) 5) Chongqing Export Processing Zone 6) Jianqiao Industrial Park 2 Wastewater Treatment in Metropolitan Chongqing Information Sources5 We obtained sewage treatment information on Metropolitan Chongqing using the following means: 1) Interviews with government officials and administrative staff at sewage treatment plants; 2) Visits to government departments such as the environmental protection department, water resources department, water authority, and municipal administrations; More than 3,000 3) Field trips to sites, and interviews with residents living near km3 of sewage treatment plants; 4) Searches of archived documents. wastewater is produced daily in The information collected includes the locations of sewage Metropolitan treatment plants in the nine districts of Metropolitan Chongqing; Chongqing, while the construction status of future and expanding sewage treatment the treatment plants; the capacity, process, and efficiency of sewage treatment; plants in the the wastewater disposal and the treatment of sludge from sewage treatment plants; the sewage drain infrastructure; the rate of region are only sewage collection; and the role of the sewage treatment designed to treat administration department. 1,416.4 km3 of wastewater per We experienced several obstacles in collecting this data, namely, day. securing permission to enter sewage treatment plants, as non-staff are prohibited from entering these plants. Once granted access, we faced problems accessing data, taking photos in plants, and organizing transportation to sewage treatment plants in remote areas. Basic Information 3 More than 3,000 km of wastewater is produced daily in Metropolitan Chongqing, half of which comes from domestic sources, while the other half comes from industrial sources. The industrial wastewater is pre-treated before being delivered to the wastewater treatment plants. There are 19 large and medium-sized wastewater treatment plants in the nine districts we studied. Together, they are designed to treat 1,416.4 km3 of wastewater per day. 3 The actual volume treated daily of 1,609 km3 represents about 54% of the total wastewater produced in Metropolitan Chongqing each day. Meanwhile, up to a hundred small treatment plants run by villages, towns, streets, and small and medium-sized industrial park zones treat an additional 510 km3 of wastewater on a daily basis, accounting for 17% of the total wastewater produced in Metropolitan Chongqing. Thus, of the 3,000 km3 of wastewater 3 produced in Metropolitan Chongqing every day, only 2,119 km , 71% of the average daily wastewater volume produced, is treated. With the recent economic growth and urban expansion of the city, the population in Metropolitan Chongqing is expected to increase to more than ten million by 2020. As a result, the amount of wastewater is also likely to increase. To manage the city’s Only 71% of the projected needs, the Chongqing municipal government is planning to expand existing wastewater treatment plants and build new ones. wastewater of the 3 Currently, 14 new wastewater treatment plants are either under 3,000 km of construction, being expanded upon, or are in the planning stages, wastewater which will increase the daily treatment capacity by 830 km3. If produced in completed as planned, the total designed daily wastewater Metropolitan treatment capacity will be 2,246.4 km3 (830 km3 + 1,416.4 km3 = 3 Chongqing every 2,246.4 km ). If those 33 plants can operate at 13.5% over capacity, as the existing 19 treatment plants have been doing, the day is treated. total daily treatment capacity will total 2,549.4 km3 (2,246.4 km3 + 303 km3). Adding the 510 km3 treated by the hundred small treatment plants run by villages, towns, streets, and small and medium-sized industrial park zones mentioned above, the total daily wastewater treatment capacity will be 3,059.4 km3. This level of wastewater treatment meets the current level of wastewater production of 3,000 km3, but does not allow for the inevitable increase in wastewater that will come from the population and economic growth expected by 2020. It also assumes that the plants can continue to operate at 13.5% over capacity and continue to meet water quality standards. Meeting these conditions is possible, but challenging. In Metropolitan Chongqing, treatment plants have been designed to meet high standards, and wastewater treated has generally met the Grade 1 water quality standard6 with COD below 60 mg/L (milligrams per litre). Presently, all of the 19 large and medium-sized treatment plants currently operating are treating water to a level of COD below 60 mg/L, with the majority of the plants investigated by this study meeting COD levels between 30- 60 mg/L. Whether or not they will continue to meet the COD standard of 60mg/L and continue to run the plants at 13.5% over capacity will depend on management standards. 4 Management standards, in turn, depend on incentives and penalties for failing to meet standards; transparency of operations to the press and the public; and the accountability of the wastewater treatment enterprises, their regulators, and lawmakers to the Chinese public. Sewage Treatment Plants Wastewater treatment plants are situated according to characteristics of geography and topography, population density in urban areas, and the planning of industrial zones. The sewage treatment plants in Metropolitan Chongqing are divided into four Whether or not categories, depending on their financing, ownership, and purpose. treatment plants These categories include: large and medium-sized sewage will meet COD treatment plants financed by the central government for point- 7 standards in the source pollution treatment, medium and small-sized sewage future will treatment plants financed by local governments, sewage treatment sites built in factories and industrial zones, and sewage treatment depend on sites built in small towns in the suburbs.